This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from my application INK JETTING APPARATUS AND A METHOD FOR MANUFACTURING THE SAME filed with the Korean Industrial Property Office on Nov. 4 1999 and there duly assigned Ser. No. 48558/1999.
1. Field of the Invention
The present invention relates to ink jetting apparatuses such as ink-jet printers, facsimile machines, etc., and more particularly to an electrostatic attraction type ink jetting apparatus having a united ink chamber and working fluid chamber capable of performing an ink jetting operation without requiring a separate working fluid chamber.
2. Description of the Related Art
Generally, ink jetting apparatuses employed in printer heads of output apparatuses such as ink-jet printers, facsimile machines, etc., jet ink in an ink chamber through a nozzle with a physical force. Such ink jetting apparatuses are grouped into a thermal type, electrostatic attraction type, piezoelectric type, and thermal-compression type according to the way of exerting physical force to the ink.
As is often the case, the process for making ink jetting apparatuses is cumbersome, complicated, lengthy and therefore expensive. Many of these processes require forming a working fluid chamber and then an ink chamber on top of the working fluid chamber. What is needed is a more simplified structure and process for forming an ink jetting apparatus. Furthermore, conventional inkjetting apparatuses require a large voltage in order to expel the ink. What is needed is a process and a structure that can expel ink with less voltage.
The present invention has been made to overcome the above-described problems of the earlier systems, and accordingly, it is an object of the present invention to provide an electrostatic attraction type ink jetting apparatus and manufacturing method thereof having a simpler manufacturing process, efficient generation of electrostatic attraction, and efficient ink discharge by integrally making the membrane together with the driving section.
Another object of the present invention is to provide an electrostatic attraction type ink jetting apparatus and manufacturing method thereof having simpler manufacturing processes by integrally forming the working fluid chamber with the ink chamber.
The above objects are accomplished by the electrostatic attraction type inkjetting apparatus according to the present invention, including: a board having an ink chamber for receiving ink supplied from an external ink supply, and a nozzle hole extending from the ink chamber to an extreme end of the board, being open at the extreme end of the board; a membrane laminated on the board; a lower electrode accommodated in the ink chamber; and an upper electrode disposed on the outer surface of the membrane. The membrane is deformed by electrostatic attraction generated while an electric potential difference is applied between the upper and lower electrodes, and the membrane is thus curved inward the ink chamber to press the ink in the ink chamber and to jet the ink outward through the nozzle hole. The membrane and upper electrode include an ink supply hole formed through the membrane and upper electrode for supplying the ink to the ink chamber therethrough.
Meanwhile, the above objects are accomplished by a method for making the electrostatic attraction type ink jetting apparatus according to the present invention, including the steps of: 1) forming an ink chamber and a nozzle hole by etching, the ink chamber for receiving ink supplied from an external ink supply and a nozzle hole extending from the ink chamber to an extreme end of a wafer and thus open at the extreme end of the wafer; 2) vapor-depositing a lower electrode in the ink chamber; 3) adhering a polyamide sheet on the wafer; 4) forming a membrane by etching the polyamide sheet; and 5) vapor-depositing an upper electrode on the membrane. Here, the step of forming the ink chamber and nozzle hole is performed by wet-etching, while the step of forming the membrane is performed by dry-etching.
Further, after the step of adhering the upper electrode, the step of forming an ink supply hole through the membrane and upper electrode for serving the function of a supply channel for ink supplied from the external ink supply to the ink chamber is performed. Here, the step of forming the ink supply hole includes the sub-steps of: a) forming an ink supply hole of the upper electrode by photo-engraving the upper electrode; and b) forming the ink supply hole of the membrane by dry-etching the membrane. In the electrostatic attraction type ink jetting apparatus and manufacturing method thereof according to the present invention, the manufacturing process becomes simpler, and driving is performed rapidly.